Electric snap switch



(ModeL) 2 Sheets-Sheet,1. G W HART ELECTRIC SNAP SWITCH.

Patented Feb. 4, 1896.

-(Model.) 2 Sheets-Sheet 2.

W. HART. ELECTRIC SNAP SWITCH.

NO. 554,221. Patented Feb-4, 1-896.

IINTTE STATES GERALD IV. HART; OF HARTFORD, CONNECTICUT, ASSIGNOR TO THEHART & IIEGEMAN MANUFACTURING COMPANY, OF SAME PLACE.

ELECTRIC SNAP-SWITCH.

SPECIFICATION forming part of Letters Patent No. 554,221, dated February4, 1896. Application filed $eptember 27, 1894. Serial No. 524,309.(ModeL) To all whom it may concern:

Be it known that I, GERALD \V. HART, of Hartford, in the county ofHartford and State of Connecticut, have invented certain new and usefulImprovements in Electric Snap- Switches, of which the following is afull, clear, and exact description, whereby any one skilled in the artcan make and use the same. My invention relates to the class of electricswitches which are actuated from a rotary shaft or spindle and operateby the winding up of a spring and the automatic-release of the catchwhich allows the switch-plate to be thrown by the recoil of the springsharply out of or into contact with terminals held on a base-plate.

The object of my invention is to provide a simple and compact switch ofthis class which shall be few as to the number of its parts and positivein operation; and to this end my invention consists in the details ofthe several parts making up the switch as a whole and in the combinationof such parts, as more particularly hereinafter described and pointedout in the claims.

Referring to the drawings, Figure 1 is a top or plan view of the switchwith cover removed. Fig. 2 is a view in side elevation of the switch.Fig. 3 is a plan view of the base, showing the socket-piece. Fig. 4 is aplan View, on enlarged scale,of the socket-piece and switch-plate withthe shaft cut in section to illustrate the operation of the spring. Fig.5 is a plan view, on enlarged scale, showing the socket-piece, and theswitch-plate in position where it is thrown by the recoil of the spring.Fig. 6 is a detail edge view of the switch-plate. Fig.7 is a de tailview in elevation,on enlarged scale, showing a modified form ofspring-support. Fig. Sis a detail top or plan view in section throughthe shaft, showing the spring in plan. Fig. 9 is a view in sideelevation of a modified form of the switch with cover removed. Fig. 10is a top or plan view of the modified form of switch. Fig. 11 is adetail view in vertical central section through the socket andswitchplate on plane denoted by line 0c 03 of Fig. 10. Fig. 12 is adetail view in central section through the socket and switch-plate onthe plane denoted by line y y of Fig. 10. Fig. 13 is a detail plan viewof the switch-plate. Fig.

14 is a detail top view, on enlarged scale, of the stop-plate and insection through the shaft, showing the shaft in one position. Fig. 15 isa detail plan view, on enlarged scale, of the stop-plate andillustrating the operation of the springarm on the rotation of theshaft.

In the accompanying drawings the letter (t denotes the base of theswitch, which may be of any suitable non-conducting material andprovided with terminals 1) and binding-posts c of ordinary construction.A rotary spindle or shaft d is mounted in the baseplate and is free toturn thereon, being rotated as by means of a handle cl, preferablyremovably secured to the upper end of the shaft.

A spring-actuated catch 6 is connected to the shaft in such manner thatthe rotary movement of the shaft winds up the spring 6 and operates towithdraw the catch e from a socket on the base-piece. The catch isformed preferably integral with the spiral spring wound into a helicalcoil, one end of the. spring being secured to the shaft d by passing itthrough a hole therein, while the other end extends downward, formingthe specific socket-engaging part or catch 9. The spring as a whole iseccentric to the shaft and is attached either at the side thereof, asshown in Figs. 2 and 4 of the drawings, or a shaft or may be so cut awayas to enable a spring a to be wound about the remainder in such mannerthat the center of the spring is eccentric to the center of the shaft,as illustrated in the modified form of Figs. 7 and 8 of the drawings.

A switch-plate g is loosely mounted on the shaft cl, so as to turnfreely thereon, although held against movement in a direction lengthwiseof the axis of the shaft. This switchplate is preferably of thin metalhaving spring-arms g forming contact-pieces which project beyond thebody of the catch-plate, so as to be thrown into or out of engagementwith the terminals 1) when the switch-plate is in one of the severalpossible positions in its rotary movement about the shaft.

The switch-plate g has an intermittent rotary movement of suchfractional part of the total revolution as may be needed to throw thecontact-pieces into or hold them out of engagement with the terminals,

Ice

My present invention is shown as embodied.

in a single-pole switch, and the switch-plate in this structure turnsone-quarter of a revolution following each release of the catch from astop-shoulder.

The base-piece preferably has fast to it a socket-plate 71 in which areformed stop-shoulders h, so constructed and shaped as to hold the catch6 against motion in any direction except by a rotary movement of theshaft. These steps are formed at the outer limits of cam-surfaces i thatextend from the stops inward toward the shaft, being placed at suchangle as will cause the catch to move toward the shaft as the latter isrotated. As soon as the catch reaches the end of such a cam it snapsover and moving forward and outward engages the next succeeding socketor stop.

The switch-plate is located between the base-plate or socket-piece andthe spring, the catch extending through a diagonal slot through theswitch-plate, the general extent and location of this slot correspondingwith the location, direction and extent of the camsurface, which isappurtenant to each socket in one form of the device.

The operation of the device is as follows: The parts being in position,as shown in Fig. l of the drawings, the shaft when rotated to the right,as by means of the handle, carries with it the spring into the positionshown in Fig. 4 of the drawings, the catch moving inward and forwardalong the cam-surfaced and the slot 76. By this rotary movement of theshaft the spring is wound up and the catch is drawn forward and inwardalong the cam until the point of the cam is reached. The spring is notonly wound up, but is revolved about the center of the shaft and movesforward, and thus in its recoil tends to sweep the catch forward andoutward. The catch also moves along the slot in the switch plate withoutmoving the latter until the inner point 2" of the cam is reached andthecatch free to be thrown forward and outward, so far as the socket-plateis concerned. The catch 6 has been drawn by this rotary movement of theshaft inward along the slot 7a in the switch-plate, and its newdirection of movement under the recoil of the spring is at an angle withthe position of the slot, so that the thrust of the catch against theouter wall of the slot tends to rotate the switch-plate on the shaft.The outward movement of the catch under the recoil of the spring and theforward movement of the catch plate are practically simultaneous, andthe movements are sharply made, so that the contact-pieces are quicklythrown into engagement or out of engagement with the terminals with aforce dependent upon the strength of the spring and the quickness of itsaction.

The form of device above described is a preferred form for somepurposes, but my in vention is not limited to the specific constructionof the several parts shown in the device embodied in Figs. 1 to 8 of thedrawings herein; but my invention is capable of ernbodiment in otherforms equally well adapted to attain the purpose in view, and in Figs. 9to 15 of the drawings there is shown and described a modified form of myinvention, which has certain features of advantage for certain uses.

In the accompanying drawings, Figs. 9 to 15, inclusive, showing themodified form of the switch, the letter a denotes the base; I), asocket-piece adapted to be secured to the base, as by means of thescrews 5 a rotary shaft 0, having a convenienthandle forturning it beingrotarily mounted in the socketpiece. At convenient regular intervalsabout the shaft and preferably located on a flange fast to the socketpiece, or forming part thereof, stops Z are arranged and preferably allat the same distance from the center of the shaft.

A switch-plate o is loosely mounted on the shaft (3 and held in anyconvenient manner, as by a flange 0 on the shaft 0, against lengthwisemovement on the shaft,the switchplate resting immediately over the platebearing the stops Z. A spring-catch 12, preferably formed of a helicalspring with a projecting arm 19, is mounted on an eccentric pin or pivotq, attached to or forming part of the shaft 0, the inner end of thespring resting against the wall of the socket in which the spring isplaced or being otherwise conveniently secured to the shaft in suchmanner as to enable the spring to be wound up or put under tension whenthe shaft is rotated, the outer end of the spring-arm engaging the stopuntil withdrawn by the continued rotary movement of the shaft and itsspring with it.

The projecting arm of the spring which terminates in the catch 7" ispreferably bent upward, so as to project through the slot 0 in theswitch-plate. The spring-arm is preferably bent close to the catch,forminga shoulder 19 which is, by the recoil of the spring, thrustagainst the stop in such manner as to prevent a return rotary movementof the shaft on which the spring is supported. The center of the pin orpivot which supports the spring is out of line with that point on thestop encountered by the shoulder and with that point of the spring whichis attached to or thrusts against the wall of the springsocket, and byreason of this location of the center of the spring out of alignmentwith the two points stated, the spring-arm as a whole acts as a stopagainst return rotary movement, as stated.

The shaft 0 is held in the socket-piece or within the base by means ofany convenient device, in the form shown an annular slot 0 beingprovided, into which a key projects through a slot b in the wall of thesocketpiece. Any other convenient method of attaching the shaft to thesocket-piece or to the base-piece, so as to provide for its free rota-IIO tion and at the same time prevent lengthwise movement of the shafton the base-piece may be provided.

Any ordinary form of terminal and binding-post may be provided, theterminals being arranged in the ordinary position to receive and to makecontact with the switchplate when the latter is in one position of itsrotary step-by-step adjustment.

The operation of the device is substantially the same as the operationdescribed in the first form which is illustrated in Figs. 1 to 8 of thedrawings, inclusive. A rotary movement of the spindle carries with itthe spring and causes the catch to be withdrawn'from contact with thestop, as indicated in full lines in Fig. 15 of the drawings, but by thecontinued rotation of the shaft the catch is finally withdrawn from thestop and then by the recoil of the spring is thrown into the positionindicated in dotted outline of Fig. 15 of the drawings, and the catchencountering the next stop holds the shaft against further rotation. Theswitch-plate being loosely mounted on the shaft is not rotated with thelatter, but by means of the upturned end of the'catch or of thespring-arm which engages the slot 0 in the switch-plate the latter ismoved quickly forward out of or into engagement with the terminals asthe spring-arm is thrown forward as soon as the catch is released fromone of the stops.

I claim as my invention.

1. In combination in a switch, a rotary shaft mounted on a base-piece,the base with a series of stops arranged about the shaft, a springsecured to the shaft so as to turn therewith and with a resilient coileccentric to the axis of the shaft and with an end adapted to engage thestops, a switch-plate loosely mounted on the shaft and loosely connectedto the arm of the spring, all substantially as described and for thepurpose specified.

2. In combination in a switch, a rotary shaft mounted on a base-piece,the base-piece with terminals and a series of stops arranged about theshaft, a spring secured to the shaft so as to turn therewith and with aresilient coil adjacent to the axis of the shaft and eccentric thereofand having a catch adapted to engage the stops, a switch-plate looselymounted on the shaft and having a slot therein receiving a projectingpart of the spring-arm, all substantially as described.

3. In combination in a switch, a rotary shaft mounted in a socket-piece,the socket-piece having a flange with a series of stops arranged aboutthe shaft, a spring attached to the shaft and revolving therewith thesaid spring having a resilient coil eccentric to the axis of the shaftand with its outer end constituting the shoulder which engages the stopson the socket-piece, a switch-plate loosely mounted on the shaft andconnected to the arm of the spring by engaging parts which permitcontraction of the spring, all substantially as described.

4. I11 combination in an electric snapswitch, a base-piece with a seriesof stops arranged at intervals about its center, a rotary shaft mountedon the base-piece, a spring secured at one end to and borne by the shaftand having a catch formed integral with the spring, and a revolubleswitch-plate loosely mounted on the shaft and loosely connected to thespring by the recoil of which said switchplate is turned as the shaft isrotated, all substantially as described.

GERALD W. HART.

\Vitnesses:

CHAS. L. BURDETT, ARTHUR B. JENKINS.

